Thermodynamic and economic analysis of the compressed air energy storage coupled with the combustible solid waste power plant

With the acceleration of the global energy transition, compressed air energy storage (CAES) technology has emerged as one of the most promising technologies to utilize renewable energy. To improve the performance of the CAES system, this paper proposes a hybrid energy system based on the CAES system and the combustible solid waste power plant (CSWPP), including combustion and gasification. In the energy storage process, low-temperature condensed water in the CSWPP regenerative system is used to absorb the compression heat of the CAES system. During the energy release process, high-temperature feedwater in the regenerative system of the CSWPP is used to heat the compressed air at the inlet of the expander in the CAES system. Subsequently, the expanded air is heated by the high-temperature flue gas in the CSWPP, and then the high-temperature air enters the combustor of the gas turbine in the CSWPP to combust with the syngas from the waste gasification, which reduces the power consumption of the original compressor and improves the system's power output. Based on the system simulation, energy, exergy, and economic analyses are conducted to evaluate system performance. The results show that the CAES subsystem's round trip and exergy efficiency can reach 82.91 % and 85.70 %, respectively, and the energy storage density is 12.49 MJ/m 3 . The total investment cost of the additional CAES subsystem is 768.20 k$, with a dynamic payback period of 3.79 years, and a net present value of 1679.14 k$. This study provides a feasible technical option for improving CAES performance. • A CAES system is integrated with a combustible solid waste power plant. • Utilization of compressed heat and air can achieve energy cascade utilization. • System integration improves efficiency of CAES system and reduces investment costs. • Energy, exergy, and economic analyses are deeply evaluated. • The round trip and exergy efficiency of the CAES subsystem are 82.91 % and 85.70 %.